Squid (weapon)
The Directorate of Miscellaneous Weapons Development ordered the Squid weapon directly from a drawing board in 1942. Engineers rushed this new anti-submarine system into active service by May 1943. The first production unit found its home aboard HMS Hadleigh Castle shortly after that date. Initial deployment occurred on board HMS Ambuscade during the same year. This rapid timeline left little room for extensive field testing before combat use began. The weapon replaced the earlier Hedgehog system to improve British naval capabilities against German U-boats. By 1959, manufacturers had produced 195 complete Squid installations for various ships.
A three-barrelled mortar formed the core structure of this ship-mounted weapon. The barrels sat mounted in series but offset slightly from each other to scatter projectiles effectively. Each projectile weighed approximately 70 pounds and carried a minol II charge inside. A clockwork time fuze determined exactly when the depth charges would detonate underwater. All three projectiles required setting to the same specific depth before firing. Operators could continuously update this depth setting right up until the moment of launch. Maximum operational depth reached roughly 600 feet below the surface. The mortars themselves were mounted in a frame capable of rotating through 90 degrees for reloading purposes.
HMS Loch Killin achieved the first successful kill using Squid on the 31st of July 1944. Over the course of the war, the system credited with sinking 17 submarines across 50 attacks. This resulted in a success ratio of 2.9 kills per attack. Conventional British depth charges managed only 85.5 kills out of 5,174 total attacks during World War II. That conventional method yielded a much lower ratio of 60.5 attacks per single kill. The Hedgehog predecessor made 268 attacks to secure just 47 kills, averaging 5.7 attacks per kill. Post-war trials later confirmed Squid was nine times more effective than standard depth charges. These statistics demonstrated clear advantages over previous anti-submarine technologies used by the Royal Navy.
Royal Canadian Navy Captain Kenneth Adams strongly opposed fitting Squid to escort vessels. He argued that installing this weapon meant sacrificing essential guns from existing ships. Those removed guns would make certain ships unsuitable for major fleet actions against enemy forces. Some officers felt the trade-off between offensive firepower and submarine hunting capability was too high. Despite these concerns, the weapon continued to be installed on frigates and corvettes throughout the conflict. The debate highlighted tensions between different naval branches regarding optimal ship configurations for wartime duties.
The Type 61 frigate Salisbury became the last ship to fire Squid in Royal Navy service during April 1977. The Swedish Navy continued using the system until 1982 when their Östergötland-class destroyers were decommissioned. Examples of the mortars now sit on display at the Explosion! Museum of Naval Firepower in Gosport, Hampshire. Another unit resides at Devonport Naval Base within the United Kingdom. A preserved installation appears on a historic ship collection vessel located in Chatham, Kent. Visitors can also view similar systems in Hamilton, Ontario and at the naval museum in Malacca, Malaysia. These displays preserve the history of British anti-submarine warfare technology for future generations.
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Common questions
When was the Squid weapon ordered and when did it enter active service?
The Directorate of Miscellaneous Weapons Development ordered the Squid weapon directly from a drawing board in 1942. Engineers rushed this new anti-submarine system into active service by May 1943.
How does the Squid depth charge mortar function compared to standard depth charges?
A three-barrelled mortar forms the core structure where each projectile weighs approximately 70 pounds and carries a minol II charge inside. Post-war trials later confirmed Squid was nine times more effective than standard depth charges used by the Royal Navy.
What were the combat statistics for the Squid weapon during World War II?
HMS Loch Killin achieved the first successful kill using Squid on the 31st of July 1944. Over the course of the war, the system credited with sinking 17 submarines across 50 attacks resulting in a success ratio of 2.9 kills per attack.
Why did some naval officers oppose fitting Squid to escort vessels?
Royal Canadian Navy Captain Kenneth Adams strongly opposed fitting Squid to escort vessels because installing this weapon meant sacrificing essential guns from existing ships. Those removed guns would make certain ships unsuitable for major fleet actions against enemy forces.
When did the Squid weapon cease operation in British and Swedish navies?
The Type 61 frigate Salisbury became the last ship to fire Squid in Royal Navy service during April 1977. The Swedish Navy continued using the system until 1982 when their Östergötland-class destroyers were decommissioned.